1. Field of Invention
This invention relates to an ophthalmic phototherapy device and an associated treatment method. More specifically, the present invention is related to a device which produces light within a preselected frequency range for being directed into the eye of a patient, and a related treatment method for promoting the healing of damaged or diseased eye tissue.
2. Description of the Related Art
It is well known that exposure of animal tissue to light can be used to modulate the activity of such biologic tissue. In this regard, exposing biologic tissue to different wavelengths of light, commonly referred to as light therapy or phototherapy, acts on different mechanisms within individual cells to promote healing and cellular rejuvenation. Accordingly, phototherapy has been utilized to treat infants for jaundice (e.g., U.S. Pat. No. 6,811,563), to treat acne and other skin conditions (e.g., U.S. Pat. No. 6,387,089), to treat rhinitis (e.g., U.S. Pat. No. 5,683,436), and to treat traumatic tissue injuries (e.g. U.S. Pat. No. 6,471,716). With respect to specific wavelengths utilized for phototherapy, and their known effects, light in the yellow range (approximately 577 nm to 597 nm) has be shown to switch off collagenase production by down-regulating MMPs and switching on new collagen production. In this regard, collagenases are enzymes that break down the native collagen that holds animal tissue together. Light in the red range (approximately 640 nm to 700 nm) has been shown to decrease inflammation in injured tissue, increase ATP production, and otherwise stimulate beneficial cellular activity. Light in the blue range (approximately 405 nm to 450 nm) has been shown to kill the propionibacterium that causes acne by activating the porphyrins produced by the bacteria.
Several commercial phototherapy devices are available including devices which utilize light-emitting diodes, or LEDs. Two such devices are the Gentlewaves® LED Photomodulation Device manufactured by Light BioScience, LLC, which includes a panel of LEDs for treating skin conditions, and the Flip4 Max7 LED device which incorporates an LED panel capable of producing multiple wavelengths of light, and which is also marketed for treating skin conditions. Further, the U.S. military and NASA have utilized small hand-held devices incorporating LED arrays that are used to reduce inflammation and promote healing. This notwithstanding, phototherapy is not in use for the purpose of promoting the healing of damaged or diseased eye tissue within the field of ophthalmology. A phototherapy device using LEDs has been utilized in an effort to strengthen corneal tissue. However, this device utilizes LEDs in the ultraviolet range to induce cross-linking of corneal collagen and, thereby, stiffen the cornea. Thus, this process, in effect, ages the tissue, as opposed to facilitating the production of new, “normal” tissue. Therefore, the process is not one in which healing of tissue is promoted.
Various phototherapy devices and procedures are disclosed in U.S. Pat. Nos. 6,677,366; 6,689,124; 6,537,302; 6,443,978; 6,287,296; 6,274,614; 6,238,424; 5,964,749; 5,766,233; 5,259,380; and 4,930,504. Other devices and procedures are disclosed in U.S. Patent Application Pub. Nos. 2003/0093135; 2003/0050674; 2002/0087207; and 2002/0004673.